Evaluation of sensitization to the crude extract of Dermatophagoides farinae and its derived allergens, Der f 2 and Zen 1, in dogs with atopic dermatitis in Southern Brazil.

BACKGROUND: Atopic dermatitis is associated with the production of IgE antibodies against environmental allergens and allergens of the house dust miteDermatophagoides farinae are frequently implicated in the disease. OBJECTIVES: We aimed to observe the allergen-specific IgE against crudeD. farinae, Der f 2 and Zen 1 in dogs with atopic dermatitis and report if these dogs are in contact with material that could shelter mite allergens. METHODS: 100 dogs with clinical diagnosis of atopic dermatitis were included after exclusion of other forms of pruritic skin disease and dogs that already received specific or non-specific immunotherapy. These dogs were of different breeds and ages and they were presented at a veterinary teaching hospital and a private service of veterinary dermatology, both located in Curitiba, Southern Brazil. At the time of anamnesis, some questions were applied to know the possibility of these dogs having had contact with furniture and textile material which could shelter house dust mites. Sera samples were obtained and further analyzed by ELISA assay to measure serum IgE levels against these allergens with an established cut-off of 0.200 IgE optical density. RESULTS: The allergen-specific IgE positivity against crudeD. farinae (92 %) and Zen 1 (77 %) was higher than Der f 2 (56 %). There was a correlation in sensitization to crude D. farinae and Zen 1 that was not observed between crude D. farinae and Der f 2 and Der f 2 and Zen 1. The sensitization to D. farinae and its allergens was associated with an unrestricted exposition to furniture and textile material. CONCLUSION & CLINICAL RELEVANCE: dogs with atopic dermatitis are frequently sensitized to D. farinae and its allergens, Der f 2 and Zen 1, may be considered major allergens in these dogs. Zen 1 may be the main allergen responsible for the sensitization to crude D. farinae.

Accumulation and aggregate formation of mutant superoxide dismutase 1 in canine degenerative myelopathy.

Canine degenerative myelopathy (DM) is an adult-onset progressive neurodegenerative disorder that has recently been linked to mutations in the superoxide dismutase 1 (SOD1) gene. We generated a polyclonal antibody against canine SOD1 to further characterize the mutant SOD1 protein and its involvement in DM pathogenesis. This antibody (SYN3554) was highly specific to canine SOD1 and had the ability to reveal distinct cytoplasmic aggregates in cultured cells expressing canine mutant SOD1 and also in the spinal neurons of symptomatic homozygotes. A similar staining pattern was observed in asymptomatic homozygotes. SOD1 aggregates were not detected in the spinal neurons of heterozygotes; the accumulation of SOD1 was also detected in the reactive astrocytes of homozygotes and heterozygotes to a similar extent. Our results support the hypothesis that the cytoplasmic accumulation and aggregate formation of the mutant SOD1 protein, especially in astrocytes, are closely associated with the pathogenesis of DM. Therefore, this disease is regarded as a spontaneous large-animal model of SOD1-mediated amyotrophic lateral sclerosis in humans.

Duodenogastric reflux induced by endoscopic submucosal dissection.

BACKGROUND AND STUDY AIMS: Endoscopic submucosal dissection (ESD) may cause excessive duodenogastric reflux (DGR) in a similar manner to distal gastrectomy, particularly after antral resections. We aimed to examine the occurrence of DGR after ESD. PATIENTS AND METHODS: Patients with gastric neoplasm for whom ESD was indicated were categorized according to lesion site: the antral group (lower [L] stomach, n = 46) and the nonantral group (upper or middle [U or M] stomach, n = 49). Endoscopy was performed before ESD, the day after ESD, and 3 months after ESD, and the fasting bile acid concentration (BAC) in the gastric juice was analyzed. RESULTS: BAC values showed significant interaction between time point and group, although this association differed in the antral and nonantral groups. BACs on the day after ESD were higher in the antral group than in the nonantral group, but not the pre-ESD and 3 months post-ESD levels. In the antral group only, fasting BACs increased significantly the day after ESD and decreased to baseline levels 3 months post-ESD. There was also a correlation between BAC and lesion location in the antral subgroups, with significantly higher BACs found the day after ESD in patients with lesser curvature lesions. CONCLUSIONS: ESD of lesions in the antral lesser curvature may lead to a transient early increase in DGR. However, ESD does not result in long-term DGR, a factor that is known to increase the risk of carcinogenesis following gastrectomy.

MAGE-A protein and MAGE-A10 gene expressions in liver metastasis in patients with stomach cancer.

Tumour samples from 71 patients with stomach cancer, 41 patients with liver metastasis (group A) and 15 patients each in stages II-IV (group B) and stage I (group C) without liver metastasis were analysed. MAGE-A protein expression was evaluated by immunohistochemistry using a 6C1 monoclonal antibody and MAGE-A10 mRNA expression was detected by highly sensitive in situ hybridisation using a cRNA probe. Expressions of MAGE-A protein and MAGE-A10 mRNA in group A were detected in 65.9 and 80.5%, respectively. Both protein and gene showed significantly higher expression in group A than those in groups B (6.7, 26.7%) and C (0, 0%) (P=0.0003, P=<0.0001, respectively). MAGE-A10 mRNA expression in liver metastasis was found in eight (88.9%) out of nine patients. The concordant rate between MAGE-A family protein expression and MAGE-A10 mRNA expression in the primary sites was 81.7% (P<0.0001). MAGE-A10 gene expression was associated with reduced survival duration. The results of this study suggest that MAGE-A10 is a possible target in active immunotherapy for advanced stomach cancer.

Chemopreventive effect of celecoxib in gastric cancer.

COX (cyclooxygenase) is one of the key enzymes involved in the synthesis of a variety of prostaglandins (PGs), some of which have been strongly linked to inflammation. One of its two well-known isoforms, COX-2, is an inducible enzyme whose induction and expression is dynamically regulated by growth factors, mitogens, and tumor promoters. Several animal and clinical studies have reported the chemopreventive effect of celecoxib, a selective COX-2 inhibitor; and in particular, a few studies have shown that celecoxib prevents the development of gastric cancer. Administration of celecoxib also showed increases in cardiovascular risk and disruption of renal physiology. Therefore, studies hoping to clarify how selective COX-2 inhibitors modulate gastric cancer must keep in mind that coxibs have also been linked to serious cardiovascular events and disruption of renal physiology.

Monocyte chemoattractant protein 1 and macrophage cyclooxygenase 2 expression in colonic adenoma.

BACKGROUND AND AIMS: Cyclooxygenase 2 (COX-2) expression in subepithelial macrophages of colorectal adenoma has been suggested as the first in a series of steps leading to colorectal tumorigenesis. We tested the hypothesis that chemokines released from human colorectal adenoma epithelium might be involved in COX-2 expression in macrophages of the lamina propria. METHODS: Endoscopic samples of sporadic colorectal adenomas were tested by enzyme linked immunosorbent assay for chemokines involved in macrophage chemotaxis. Localisation of adenoma macrophage chemoattractant protein 1 (MCP-1) and COX-2 were determined by immunohistochemistry. The effects of MCP-1, in the presence or absence of celecoxib, on COX-2 expression, and prostaglandin (PG) E(2) and vascular endothelial growth factor (VEGF) release, were examined in human macrophages isolated from peripheral blood. RESULTS: MCP-1 levels were markedly higher in adenoma with mild-moderate dysplasia (129.7 (19.9) pg/mg protein) and severe dysplasia (227.9 (35.4) pg/mg protein) than in normal colonic mucosa (55.8 (4.2) pg/mg protein). Other chemokine levels, macrophage inflammatory proteins (MIP)-1alpha and MIP-1beta, and the chemokine regulated on activation of normal T cell expressed and secreted (RANTES) did not vary significantly between adenoma and normal mucosa. MCP-1 levels in both adenoma and normal colonic mucosa increased significantly three hours after tissue cultivation in vitro. MCP-1 immunoreactivity was restricted to the adenoma epithelium, with no reactivity seen in adjacent normal epithelial cells. MCP-1 stimulated COX-2 expression and PGE(2) and VEGF release in human macrophages. Celecoxib, a selective COX-2 inhibitor, inhibited MCP-1-induced PGE(2) and VEGF release in macrophages. Addition of exogenous PGE(2) reversed this inhibitory effect on VEGF release, suggesting that MCP-1 in adenoma epithelial cells might be involved in COX-2 expression and subsequent macrophage activation. CONCLUSIONS: MCP-1 in colorectal adenoma epithelial cells might be involved in macrophage migration and COX-2 expression, leading to the subsequent development of colonic adenoma.

Preventive therapy for non-steroidal anti-inflammatory drug-induced ulcers in Japanese patients with rheumatoid arthritis: the current situation and a prospective controlled-study of the preventive effects of lansoprazole or famotidine.

BACKGROUND: There is a lack of evidence for the efficacy of preventive medications for peptic ulcers (PUs) among long-term users of non-steroidal anti-inflammatory drugs (NSAIDs) in Japan. AIM: To estimate the preventive effect by normal dose, not high-dose histamine-H2 receptor antagonists (H2RA) for NSAID-induced ulcers. METHODS: We designed two different studies to assess the efficacy of anti-ulcer agents in rheumatoid arthritis (RA) in patients treated over a long term with NSAIDs. An investigative survey divided patients into those not taking anti-ulcer agents (non-medication group); those taking mucosal protective agents (mucosal protectant group), H2RA (H2RA group), proton pump inhibitors (PPI group), or a prostaglandin E1 analog (PG) (PG group). The second study compared prospectively the preventive effects of either famotidine 20 mg bd (famotidine group) or lansoprazole 15 mg daily (lansoprazole group) in patients with PU scars. RESULTS: The prevalence of PU in the H2RA group was significantly lower compared to the mucosal protectant group (P < 0.05), and the mucosal protectant group was not significantly different to the non-medication group. The prospective study revealed that the PU onset rate of the famotidine group was 8% (1/13), and lansoprazole group was 15% (2/13), indicating no significant differences between the two. CONCLUSIONS: In Japan, normal-dose H2RA is expected to be a new PU preventive treatment strategy in patients requiring long-term NSAID therapy.

Implications of corpus gastritis, atrophy and cyclooxygenase in the development of gastric erosions after curing Helicobacter pylori infection.

BACKGROUND: Helicobacter pylori eradication decreases recurrence of peptic ulcers with marked improvement in histological inflammation, but gastric mucosal injuries may be developed even after eradication. PURPOSE: To investigate the mechanisms responsible for the development of gastric erosions after eradication, we analysed the relationship between clinicopathological risk factors and the occurrence of gastric erosion after curing H. pylori infection. PATIENTS: Sixty patients underwent endoscopy before, and 3, 6 and 12 months after the completion of H. pylori eradication. METHODS: Risk factors associated with the development of gastric erosions after eradication were assessed by multivariate analysis, and cyclooxygenase-1 and -2 immunoreactivity was histologically examined in the gastric mucosa before and after eradication. RESULTS: The cumulative prevalence of gastric erosions after H. pylori eradication was 38.3% within 1 year. Using multivariate analysis, corpus gastritis scores (inflammation score+activity score), corpus atrophy scores and an age of more than 50 years were found to be independent factors associated with the development of gastric erosion after eradication with odds ratios of 7.39, 0.13 and 5.00, respectively. Cyclooxygenase-2 immunoreactivity of the corpus was decreased for the non-erosion group after eradication, but not for the erosion group. CONCLUSIONS: Severe gastritis or less severe atrophy in oxyntic glands but not in pyloric glands before eradication may be involved in the development of gastric erosions after curing H. pylori infection.

Identification of peptides containing T-cell epitopes of Japanese cedar (Cryptomeria japonica) pollen allergen (Cry j 1) in dogs.

Japanese cedar (Cryptomeria japonica, CJ) pollen has been known to cause atopic dermatitis in dogs in Japan. However, since the mechanism of the CJ antigen recognition is not well understood in dogs, it is difficult to develop effective immunotherapy for atopic dermatitis caused by sensitization to CJ pollen. In order to aim at development of a peptide immunotherapy, we tried to identify T-cell epitopes of a major allergen of CJ pollen, Cry j 1, in dogs sensitive to CJ pollen allergen. Peripheral blood mononuclear cells (PBMCs) obtained from 22 dogs experimentally sensitized to CJ pollen allergen and 5 atopic dogs sensitive to CJ pollen allergen were used for mapping of T-cell epitopes of Cry j 1 using 35 kinds of synthesized overlapping peptides of Cry j 1. Reactive peptides were identified based on the results of blastogenic responses of PBMCs against the peptides when the stimulation indices were beyond 2.0. Three reactive peptides were identical in a relatively high population of experimental dogs, which were Nos. 8 (p71-90) (41%), 10 (p91-110) (50%), and 11 (p101-120) (41%). It was considered that these synthesized peptides should contain T-cell epitopes of Cry j 1 in the dogs. However, there were no reactive peptides identical among the five atopic dogs spontaneously sensitive to CJ pollen. The population of dogs experimentally sensitized to CJ pollen antigen will be used in order to investigate effects of a peptide immunotherapy using the reactive peptides. The results in atopic dogs sensitive to CJ pollen antigen will also provide useful information on necessity to develop a tailor-made immunotherapy using reactive peptides in each dog.

Monocyte chemoattractant protein 1 (MCP-1) released from Helicobacter pylori stimulated gastric epithelial cells induces cyclooxygenase 2 expression and activation in T cells.

BACKGROUND: and aims: To clarify the interaction between gastric epithelial and mucosal T cells, we examined the role of cytokines released from epithelial cells in response to Helicobacter pylori water extract protein (HPWEP) in regulating T cell cyclooxygenase 2 (COX-2) expression and activation. METHODS: Media from MKN-28 cells incubated with HPWEP for 48 hours were added to Jurkat T cells and human peripheral T cells. C-C and CXC chemokine concentrations in MKN-28 cell media, and COX-2 expression, interferon gamma (IFN-gamma), and interleukin (IL)-4 secretions in T cells were determined by western blot analysis and ELISA methods. Distributions of COX-2 positive T cells and monocyte chemoattractant protein 1 (MCP-1) in tissue specimens with H pylori associated gastritis were determined as single or double labelling by immunohistochemistry. RESULTS: MCP-1, IL-7, IL-8, and RANTES were detected in media from MKN-28 cells incubated with HPWEP. Media as a whole, and MCP-1 alone, stimulated COX-2 expression and peripheral T cell proliferation. Anti-MCP-1 antibody inhibited media stimulated COX-2 mRNA expression in Jurkat T cells. Media stimulated IFN-gamma but not IL-4 secretion from peripheral T cells, while MCP-1 stimulated IL-4 but not IFN-gamma secretion. Both stimulated cytokine release, and peripheral T cell proliferation was partially inhibited by NS-398, a specific COX-2 inhibitor. In mucosa with gastritis, COX-2 was expressed in T cells and MCP-1 was localised mainly in epithelial and mononuclear cells. MCP-1 levels and the intensity of COX-2 expression in tissue samples were closely related. CONCLUSIONS: Cytokines such as MCP-1, released from gastric epithelial cells in response to HPWEP, seem to modulate T cell immune responses, at least in part via COX-2 expression.

Differential expression of secreted frizzled-related protein 4 in decidual cells during pregnancy.

During pregnancy, the uterus shows marked morphological and physiological changes under the regulation of ovarian steroid. To elucidate the molecular cues of these changes, we tried to identify the transcripts differentially expressed in the pregnant rat uterus by using the suppression subtractive hybridization method. Seven independent clones were isolated and one of the up-regulated genes was secreted frizzled-related protein 4 (sFRP4). sFRP4 contains a Wnt-binding domain and belongs to the secreted frizzled protein family whose members are assumed to function as modulators of the Wnt signal. The expression level of sFRP4 mRNA reached a peak in the pregnant uterus on day 12, when uterine decidualization was almost complete in the rat. In situ hybridization histochemistry revealed that sFRP4 transcripts were observed in the decidual cells. In addition, proliferating cell nuclear antigen (PCNA)-positive cells were shown to be overlapped in decidua, suggesting that sFRP4 mRNA expression was accompanied by the late phase of decidual cell proliferation. Moreover, sFRP4 and estrogen receptor-alpha transcripts were co-localized. Furthermore, we analyzed the regulation of sFRP4 by estrogen using 17 beta-estradiol-treated ovariectomized rats. sFRP4 mRNA was detected in the uterus at 48 h after estrogen treatment, especially in endometrial stroma where PCNA-positive cells were also observed. The results in this study led us to the notion that sFRP4 mRNA may be up-regulated after estrogen treatment in the late phase of uterine cell proliferation.

Effect of acid suppression therapy on development of gastric erosions after cure of Helicobacter pylori infection.

BACKGROUND: Helicobacter pylori eradication markedly improves histological inflammation and decreases peptic ulcer recurrence, but little is known about the subsequent development of gastric mucosal injury. AIM: To investigate whether acid suppression treatment after eradication influences the development of gastric erosions. METHODS: Eighty-one patients (gastritis or peptic ulcer) after successful H. pylori eradication were divided into two groups: 40 received an H2-blocker for 6 months (H2-blocker-positive) and 41 received no treatment (H2-blocker-negative). Endoscopy was performed before, and at 3 and 6 months after completion of eradication. RESULTS: Cumulative prevalence of gastric erosions in the H2-blocker-positive group was significantly lower than in the H2-blocker-negative group, 25% vs. 42%, respectively. In the H2-blocker-negative group but not the H2-blocker-positive group, the cumulative prevalence of gastric erosions after eradication was higher in patients with less severe corpus atrophy or more severe corpus gastritis. CONCLUSIONS: Development of gastric erosions after H. pylori eradication may be controlled by acid suppression treatment. Less severe atrophy or more severe gastritis in oxyntic glands before eradication may be involved in the development of gastric erosions. These results support the idea that recovery of acid secretion may be one of factors for development of gastric mucosal erosions after successful eradication.

Inhibition of Helicobacter pylori-induced cyclo-oxygenase-2 aggravates NSAID-caused gastric damage in Mongolian gerbils.

BACKGROUND: The effect of Helicobacter pylori infection on non-steroidal anti-inflammatory drug-induced gastric mucosal injury is controversial. AIM: To examine the effect of the interaction between H. pylori and non-steroidal anti-inflammatory drugs on gastric mucosal injury. METHODS: Mongolian gerbils infected with H. pylori were treated with indometacin at 8 mg/kg for 2 days or 7 days. Mucosal damage was assessed by macroscopic and histological examination, and myeloperoxidase activity was measured as an index of neutrophil infiltration. The expression levels of cyclo-oxygenase proteins were determined by Western blot analysis and cyclo-oxygenase activity. RESULTS: A 2-day course of indometacin did not cause an increase in gastric damage in H. pylori-infected Mongolian gerbils compared to uninfected gerbils, while a 7-day course of indometacin caused additive gastric damage in H. pylori-infected animals. H. pylori infection induced cyclo-oxygenase-2 expression in the stomach. Treatment with indometacin for 2 days did not significantly affect cyclo-oxygenase activity in H. pylori-infected animals, while treatment for 7 days inhibited both cyclo-oxygenase-1 and cyclo-oxygenase-2 activities. Pre-treatment with a selective cyclo-oxygenase-2 inhibitor aggravated mucosal injury in H. pylori-infected animals treated or not treated with indometacin for 2 days. CONCLUSIONS: Our results suggest that cyclo-oxygenase-2 protein induced by H. pylori infection may be involved in the defence of the gastric mucosa against damage caused by non-steroidal anti-inflammatory drugs. Therefore, inhibition of cyclo-oxygenase-2 activity may enhance non-steroidal anti-inflammatory drug-caused gastric damage in H. pylori-infected animals.

Dickkopf1 is required for embryonic head induction and limb morphogenesis in the mouse.

Dickkopf1 (Dkk1) is a secreted protein that acts as a Wnt inhibitor and, together with BMP inhibitors, is able to induce the formation of ectopic heads in Xenopus. Here, we show that Dkk1 null mutant embryos lack head structures anterior of the midbrain. Analysis of chimeric embryos implicates the requirement of Dkk1 in anterior axial mesendoderm but not in anterior visceral endoderm for head induction. In addition, mutant embryos show duplications and fusions of limb digits. Characterization of the limb phenotype strongly suggests a role for Dkk1 both in cell proliferation and in programmed cell death. Our data provide direct genetic evidence for the requirement of secreted Wnt antagonists during embryonic patterning and implicate Dkk1 as an essential inducer during anterior specification as well as a regulator during distal limb patterning.

Aging increases, and duodenal ulcer reduces the risk for intestinal metaplasia of the gastric corpus in Japanese patients with dyspepsia.

BACKGROUND AND AIMS: The classification of gastritis by using the revised Sydney system suggests that there are two types of Helicobacter pylori-related gastritis. The aim of the present study was to examine the risk factors that might be involved in the presence of either atrophic gastritis or intestinal metaplasia of the gastric corpus of Japanese patients. METHODS: Biopsy samples were obtained from the gastric corpus in 154 patients with dyspepsia, and the degree of atrophy or intestinal metaplasia was determined histologically. The correlation between several variables and presence of atrophy or intestinal metaplasia was evaluated by using multivariate analysis. RESULTS: Among the 11 variables, which included age, peptic ulcer diseases and H. pylori infection, H. pylori infection was the major risk factor associated with the presence of atrophic gastritis or intestinal metaplasia of the gastric corpus. In contrast, duodenal ulcer (DU) disease reduced the risk of contracting both conditions. Age was an independent risk factor only for intestinal metaplasia of the gastric corpus. When 128 H. pylori-positive subjects were analyzed, DU and age were similarly associated with the presence of both conditions. CONCLUSIONS: These results suggest that DU reduces the risk for contracting atrophic gastritis and intestinal metaplasia, and age is an independent risk factor for intestinal metaplasia of the gastric corpus in dyspeptic Japanese patients.

Evidence that members of the Cut/Cux/CDP family may be involved in AER positioning and polarizing activity during chick limb development.

In vertebrates, the apical ectodermal ridge (AER) is a specialized epithelium localized at the dorsoventral boundary of the limb bud that regulates limb outgrowth. In Drosophila, the wing margin is also a specialized region located at the dorsoventral frontier of the wing imaginal disc. The wingless and Notch pathways have been implicated in positioning both the wing margin and the AER. One of the nuclear effectors of the Notch signal in the wing margin is the transcription factor cut. Here we report the identification of two chick homologues of the Cut/Cux/CDP family that are expressed in the developing limb bud. Chick cux1 is expressed in the ectoderm outside the AER, as well as around ridge-like structures induced by (&bgr;)-catenin, a downstream target of the Wnt pathway. cux1 overexpression in the chick limb results in scalloping of the AER and limb truncations, suggesting that Cux1 may have a role in limiting the position of the AER by preventing the ectodermal cells around it from differentiating into AER cells. The second molecule of the Cut family identified in this study, cux2, is expressed in the pre-limb lateral plate mesoderm, posterior limb bud and flank mesenchyme, a pattern reminiscent of the distribution of polarizing activity. The polarizing activity is determined by the ability of a certain region to induce digit duplications when grafted into the anterior margin of a host limb bud. Several manipulations of the chick limb bud show that cux2 expression is regulated by retinoic acid, Sonic hedgehog and the posterior AER. These results suggest that Cux2 may have a role in generating or mediating polarizing activity. Taking into account the probable involvement of Cut/Cux/CDP molecules in cell cycle regulation and differentiation, our results raise the hypothesis that chick Cux1 and Cux2 may act by modulating proliferation versus differentiation in the limb ectoderm and polarizing activity regions, respectively.

Localisation of cyclooxygenase 1 and cyclooxygenase 2 in Helicobacter pylori related gastritis and gastric ulcer tissues in humans.

BACKGROUND: Prostaglandin endoperoxide synthase/cyclooxygenase (COX) is the key enzyme in gastric mucosal protection and repair but its cellular localisation in the human stomach is still unclear. AIMS: To investigate immunohistochemically the cellular distribution of COX-1 and COX-2 proteins in the human stomach with or without gastritis or ulceration. PATIENTS AND METHODS: Tissues were obtained by surgical resection of gastric ulcers associated with perforation (n = 9) or by biopsy from Helicobacter pylori positive patients with gastric ulcers (n = 45) and H pylori negative healthy subjects (n = 15). COX expression was detected by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR), western blotting, and light and electron microscopic immunohistochemistry. RESULTS: COX-2 mRNA and protein were detected in gastric ulcer tissues but not in intact gastric mucosa. COX-1 mRNA and protein were detected in the intact mucosa. COX-2 immunostaining was exclusively localised in macrophages and fibroblasts between necrotic and granulation tissues of the ulcer bed. The percentage of COX-2 expressing cells was significantly higher in open than in closed ulcers, and in gastritis than in gastric mucosa without H pylori infection. COX-1 immunoreactivity localised in lamina propria mesenchymal cells was similar in various stages of ulcer disease and in intact gastric mucosa. Electron microscopic immunohistochemistry revealed both COX-1 and COX-2 on the luminal surfaces of the endoplasmic reticulum and nuclear envelope of macrophages and fibroblasts. CONCLUSIONS: Our results showed that COX-2 protein was induced in macrophages and fibroblasts in gastric ulcers and H pylori related gastritis, suggesting its involvement in the tissue repair process.

Induction of cyclooxygenase-2 in mesothelial cells in peritonitis caused by perforated ulcers--an immunohistochemical study in humans.

BACKGROUND: Increasing evidence suggests that mesothelial cells contribute to the control of inflammation in the peritoneal cavity by secreting prostaglandins. A study has shown that cyclooxygenase (COX)-2 knockout mice die partly as a result of peritonitis. AIM: To investigate the expression and location of COX in peritonitis associated with peptic ulcer perforation. METHODS: Gastric and duodenal tissues were collected intraoperatively from nine and four patients, respectively, and immunohistochemical staining for COX-1 and COX-2 was performed. RESULTS: Histologically, all patients had severe peritonitis around the perforation sites, into which many inflammatory cells and fibroblasts had infiltrated, and reactive mesothelial cells exhibited hyperplastic change. The COX-1 protein was not detected, whereas COX-2 was abundant in reactive mesothelial cells near the perforation site and disappeared away from the site. Macrophages and fibroblasts around the perforation site also revealed immunostaining for COX-2. CONCLUSIONS: Our results showed that COX-2 protein is induced in mesothelial cells, as well as in macrophages and fibroblasts, in inflamed peritoneal tissues associated with peptic ulcer perforation, suggesting involvement of COX-2 in tissue repair.

Multiple left-right asymmetry defects in Shh(-/-) mutant mice unveil a convergence of the shh and retinoic acid pathways in the control of Lefty-1.

Asymmetric expression of Sonic hedgehog (Shh) in Hensen's node of the chicken embryo plays a key role in the genetic cascade that controls left-right asymmetry, but its involvement in left-right specification in other vertebrates remains unclear. We show that mouse embryos lacking Shh display a variety of laterality defects, including pulmonary left isomerism, alterations of heart looping, and randomization of axial turning. Expression of the left-specific gene Lefty-1 is absent in Shh(-/-) embryos, suggesting that the observed laterality defects could be the result of the lack of Lefty-1. We also demonstrate that retinoic acid (RA) controls Lefty-1 expression in a pathway downstream or parallel to Shh. Further, we provide evidence that RA controls left-right development across vertebrate species. Thus, the roles of Shh and RA in left-right specification indeed are conserved among vertebrates, and the Shh and RA pathways converge in the control of Lefty-1.

A model for CD8+ CTL tumor immunosurveillance and regulation of tumor escape by CD4 T cells through an effect on quality of CTL.

Understanding immune mechanisms influencing cancer regression, recurrence, and metastasis may be critical to developing effective immunotherapy. Using a tumor expressing HIV gp160 as a model viral tumor Ag, we found a growth-regression-recurrence pattern, and used this to investigate mechanisms of immunosurveillance. Regression was dependent on CD8 T cells, and recurrent tumors were resistant to CTL, had substantially reduced expression of epitope mRNA, but retained the gp160 gene, MHC, and processing apparatus. Increasing CTL numbers by advance priming with vaccinia virus expressing gp160 prevented only the initial tumor growth but not the later appearance of escape variants. Unexpectedly, CD4 cell depletion protected mice from tumor recurrence, whereas IL-4 knockout mice, deficient in Th2 cells, did not show this protection, and IFN-gamma knockout mice were more susceptible. Purified CD8 T cells from CD4-depleted mice following tumor regression had more IFN-gamma mRNA and lysed tumor cells without stimulation ex vivo, in contrast to CD4-intact mice. Thus, the quality as well as quantity of CD8+ CTL determines the completeness of immunosurveillance and is controlled by CD4 T cells but not solely Th2 cytokines. This model of immunosurveillance may indicate ways to enhance the efficacy of surveillance and improve immunotherapy.